Dynamics of Consciousness

2010 ◽  
Vol 24 (2) ◽  
pp. 141-148 ◽  
Author(s):  
F. T. Arecchi
Keyword(s):  
Degrees Of Freedom ◽  
Loss Rate ◽  
Deterministic Chaos ◽  
Collective State ◽  
Control Of Chaos ◽  
Time Control ◽  
Cognitive Problem ◽  
Neuron Synchronization ◽  
The Brain ◽  
Neuron Dynamics

The cognitive problem is how a given sensorial input elicits a decision. Since the neuron dynamics are affected by deterministic chaos, information is lost over the course of time. Control of chaos reduces such a loss rate by adding extra degrees of freedom. This addition is a change of code; such a recoding occurs on two time scales, namely, (A) the cognitive one (lasting up to 3 s), within which the brain reaches a collective state associated with a perception, and (B) the linguistic one (beyond 3 s), whereby memory retrieves different (A) units and compares them. In (A) the neurons are mutually coupled in large networks; collective synchronization of neuron arrays elicit decisions. In (B), different (A) slots are compared after retrieval. This requires a subject to be conscious of him/herself as well as that the pieces of the stream be correlated. While in (A) the neuron synchronization is described in dynamic terms, in (B) the slot comparison is formalized by an inverse Bayes rule. Distinction of (A), where coherent perceptions are built, from (B), where we formulate attributions of truth, recovers the fundamental philosophical difference between apprehension and judgment.

Complexity Measures of Brain Electrophysiological Activity

2010 ◽  
Vol 24 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Włodzimierz Klonowski ◽  
Pawel Stepien ◽  
Robert Stepien
Keyword(s):  
Brain Activity ◽  
Deterministic Chaos ◽  
Epileptic Seizures ◽  
Eeg Signal ◽  
Eeg Signals ◽  
Complexity Measures ◽  
Electrophysiological Activity ◽  
Signal Complexity ◽  
Physiological Sleep ◽  
The Brain

Over 20 years ago, Watt and Hameroff (1987 ) suggested that consciousness may be described as a manifestation of deterministic chaos in the brain/mind. To analyze EEG-signal complexity, we used Higuchi’s fractal dimension in time domain and symbolic analysis methods. Our results of analysis of EEG-signals under anesthesia, during physiological sleep, and during epileptic seizures lead to a conclusion similar to that of Watt and Hameroff: Brain activity, measured by complexity of the EEG-signal, diminishes (becomes less chaotic) when consciousness is being “switched off”. So, consciousness may be described as a manifestation of deterministic chaos in the brain/mind.

scholarly journals Exact mapping between a laser network loss rate and the classical XY Hamiltonian by laser loss control

Nanophotonics ◽  
2020 ◽  
Vol 9 (13) ◽  
pp. 4117-4126 ◽  
Author(s):  
Igor Gershenzon ◽  
Geva Arwas ◽  
Sagie Gadasi ◽  
Chene Tradonsky ◽  
Asher Friesem ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Loss Rate ◽  
Oscillation Amplitude ◽  
Xy Model ◽  
Spin Hamiltonian ◽  
Laser Oscillator ◽  
Physical Systems ◽  
Network State ◽  
Spin Hamiltonians ◽  
Loss Control

AbstractRecently, there has been growing interest in the utilization of physical systems as heuristic optimizers for classical spin Hamiltonians. A prominent approach employs gain-dissipative optical oscillator networks for this purpose. Unfortunately, these systems inherently suffer from an inexact mapping between the oscillator network loss rate and the spin Hamiltonian due to additional degrees of freedom present in the system such as oscillation amplitude. In this work, we theoretically analyze and experimentally demonstrate a scheme for the alleviation of this difficulty. The scheme involves control over the laser oscillator amplitude through modification of individual laser oscillator loss. We demonstrate this approach in a laser network classical XY model simulator based on a digital degenerate cavity laser. We prove that for each XY model energy minimum there corresponds a unique set of laser loss values that leads to a network state with identical oscillation amplitudes and to phase values that coincide with the XY model minimum. We experimentally demonstrate an eight fold improvement in the deviation from the minimal XY energy by employing our proposed solution scheme.

Real Time, Near-Optimal Trajectory Planning of an Omni-Directional Vehicle

2001 ◽  
Author(s):  
Tamás Kalmár-Nagy ◽  
Pritam Ganguly ◽  
Raffaello D’Andrea
Keyword(s):  
Real Time ◽  
Optimal Trajectory ◽  
Degrees Of Freedom ◽  
Dynamic Environments ◽  
Real Time Control ◽  
Uncertain Environments ◽  
Time Control ◽  
Innovative Method ◽  
Optimal Trajectory Planning ◽  
Three Degrees Of Freedom

Abstract In this paper, we discuss an innovative method of generating near-optimal trajectories for a robot with omni-directional drive capabilities, taking into account the dynamics of the actuators and the system. The relaxation of optimality results in immense computational savings, critical in dynamic environments. In particular, a decoupling strategy for each of the three degrees of freedom of the vehicle is presented, along with a method for coordinating the degrees of freedom. A nearly optimal trajectory for the vehicle can typically be calculated in less than 1000 floating point operations, which makes it attractive for real-time control in dynamic and uncertain environments.

scholarly journals Virtualization of Robotic Hands Using Mobile Devices †

Robotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Santiago T. Puente ◽  
Lucía Más ◽  
Fernando Torres ◽  
and Francisco A. Candelas
Keyword(s):  
Degrees Of Freedom ◽  
Robotic Hand ◽  
Robot Hand ◽  
Real Time Control ◽  
Robotic Hands ◽  
Robot Operating System ◽  
Server Side ◽  
Time Control ◽  
Unity 3D ◽  
Real Robot

This article presents a multiplatform application for the tele-operation of a robot hand using virtualization in Unity 3D. This approach grants usability to users that need to control a robotic hand, allowing supervision in a collaborative way. This paper focuses on a user application designed for the 3D virtualization of a robotic hand and the tele-operation architecture. The designed system allows for the simulation of any robotic hand. It has been tested with the virtualization of the four-fingered Allegro Hand of SimLab with 16 degrees of freedom, and the Shadow hand with 24 degrees of freedom. The system allows for the control of the position of each finger by means of joint and Cartesian co-ordinates. All user control interfaces are designed using Unity 3D, such that a multiplatform philosophy is achieved. The server side allows the user application to connect to a ROS (Robot Operating System) server through a TCP/IP socket, to control a real hand or to share a simulation of it among several users. If a real robot hand is used, real-time control and feedback of all the joints of the hand is communicated to the set of users. Finally, the system has been tested with a set of users with satisfactory results.

The history of brain retractors throughout the development of neurological surgery

2014 ◽  
Vol 36 (4) ◽  
pp. E8 ◽  
Author(s):  
Rachid Assina ◽  
Sebastian Rubino ◽  
Christina E. Sarris ◽  
Chirag D. Gandhi ◽  
Charles J. Prestigiacomo
Keyword(s):  
Degrees Of Freedom ◽  
Brain Parenchyma ◽  
Neurosurgical Procedures ◽  
Intracranial Surgery ◽  
Different Types ◽  
History Of ◽  
Brain Retraction ◽  
Neurological Surgery ◽  
The 19Th Century ◽  
The Brain

Early neurosurgical procedures dealt mainly with treatment of head trauma, especially skull fractures. Since the early medical writings by Hippocrates, a great deal of respect was given to the dura mater, and many other surgeons warned against violating the dura. It was not until the 19th century that neurosurgeons started venturing beneath the dura, deep into the brain parenchyma. With this advancement, brain retraction became an essential component of intracranial surgery. Over the years brain retractors have been created pragmatically to provide better visualization, increased articulations and degrees of freedom, greater stability, less brain retraction injury, and less user effort. Brain retractors have evolved from simple handheld retractors to intricate brain-retraction systems with hand-rest stabilizers. This paper will focus on the history of brain retractors, the different types of retractors, and the progression from one form to another.

Dynamic Control of Curve-Constrained Hyper-Redundant Manipulators

2004 ◽  
Vol 16 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Shugen Ma ◽  
◽  
Mitsuru Watanabe ◽  
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Control ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Real Time Control ◽  
Feed Forward ◽  
Manipulator Dynamics ◽  
Time Control ◽  
Control Scheme ◽  
Feed Forward Controller

Hyper-redundant manipulators have high number of kinematic degrees of freedom, and possess unconventional features such as the ability to enter narrow spaces while avoiding obstacles. To control these hyper-redundant manipulators accurately, manipulator dynamics should be considered. This is, however, time-comsuming and makes implementation of real-time control difficult. In this paper, we propose a dynamic control scheme for hyper-redundant manipulators, which is based on analysis in defined posture space where three parameters were used to determine the manipulator posture. Manipulator dynamics are modeled on the parameterized form with the parameter of the posture space path. The posture space path-tracking feed-forward controller is then formulated on the basis of a parameterized dynamic equation. Computer simulation, in which a hyper-redundant manipulator traces the posture space path well by using the proposed feed-forward controller, proved that the hyper-redundant manipulator tracks the workspace path accurately.

Paper 16: A Preliminary Investigation into the Effects of Applying a Locking Device to a Position-Controlled Externally Powered Prosthesis

1968 ◽  
Vol 183 (10) ◽  
pp. 93-97
Author(s):  
J. M. Pottinger ◽  
N. D. Ring
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Preliminary Investigation ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Time Control ◽  
Dynamic Phase ◽  
Static Phase ◽  
Powered Prosthesis

The application of position control to externally powered prosthetic arms leads to increased function and versatility when compared to a prosthetic system with open-loop control. However, various compromises are necessary owing to the limited number of available control sites. An investigation is being conducted into the possibility of combining the advantages of position control during the dynamic phase of movement with the locking facility of velocity–time control during the static phase, which leads to a larger number of available control sites and thus a greater number of degrees of freedom.

Design and its characteristic analysis of a wheeled train uncoupling robot with multi-degrees-of-freedom

2015 ◽  
Vol 230 (10) ◽  
pp. 1673-1684 ◽  
Author(s):  
Jianjun Yao ◽  
Yuxuan Huang ◽  
Guilin Jiang ◽  
Shuang Gao ◽  
Rui Xiao ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Robot Manipulator ◽  
Vital Role ◽  
Real Time Control ◽  
Characteristic Analysis ◽  
Time Control ◽  
Operational Space ◽  
Wheeled Robot ◽  
Marshalling Yard ◽  
Cargo Transportation

Freight trains play a vital role in cargo transportation in the world. The freight cars need to be redistributed for marshalling according to different destinations in the hump yard. Humans are usually employed to uncouple the freight cars in the marshalling yard. However, the work environment is difficult to work in, because of its potential danger and the effects of the surrounding environment can have a very serious impact on human’s health. A wheeled robot is developed to replace humans to finish the uncoupling task. It has four degrees-of-freedom with flexible motion. Based on the D-H method, the kinematics, including the forward and the inverse kinematics, is firstly analysed. The dynamic analysis is then studied by Newton–Euler equations. The workspace is lastly investigated to verify its operational space such that the coupler can be easily reached by the robot manipulator. Those characteristic analyses provide a basis for motion planning and real-time control of the robot.

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